Rotary impact-pulverizer



C. J. TOMLINSON.

ROTARY IMPACT PULVERIZER.

APPLICATION FILED 05c. 23, 1915.

Patented Feb. 24, 1920.

UNITED STATES PATENT OFFICE.

CLIFFORD J. TOMLINSON. OF WEST ALLIS, WISCONSIN, ASSIGNOR T0 ALLIS-CHALMEBS MANUFACTURING COMPANY, 01 MILWAUKEE, WISCONSIN, A CORPORATION 01' DELAWARE.

ROTARY IKPAC'I PULVEBIZEB.

Specification of Letters Patent.

Patented Feb. 24, 1920.

Application filed becember 2a, 1915. Serial No. cases.

To all whom it may concern:

Be it known that I. CLIFFORD J. TOMLIN- sox, a citizen of the.- United States. residing at Vest Allis, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in Rotary Impact-Pulverizers, of which the following is a. specification.

This invention relates to improvements in the construction of rotary impact pulverizers of the type in whichthe materlal is reduced by impact with a plurality of revolving hammers.

An object of the invention is to provide a rotary impact pulverizer which is simple in construction and eflicient in operation. One of the more specific objects is to provide an efii'cient rotary impact pulverizer of large capacity which is operable at relatively low speed. Another object is to pro.- vide a ulverizer in which wear on the elements is reduced to a minimum. A further object is to provide a pulverizer in which possibility of injury of the machine due to abnormal conditions of operation is reduced to a minimum.

These and other objects are accomplished by providing a pair of spaced rotors having opposed impact surfaces, with means for positively causing predetermined impact surfaces to cooperate for crushing. The r0- tors are caused to rotate in the same direction and have a pulverizing chamber or zone formed between them, which is maintained substantially free from air currents in order to eliminate interference with the pulverizing action. The pulverizing rotors are furthermore mounted in a novel man ner in order to permit ready feeding of the material to the pulverizing zone. The pulverizer is also provided with means for returnin the uncrushed material directly to the pn verizing zone, in order to confine the disintegration to the pulverizing chamber, and also to obtain a more uniform product at the discharge.

A clear conception of an embodiment of the invention may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate similar arts.

The single figure of the drawing discloses acentral vertical section through a rotar impact pulverizer built in accordance wit this invention.

The pulverizer comprises essentially a housing or casing 3 having the rotors 1, 2, mounted therein. The rotor 1 is secured to the horizontal shaft 8, while the rotor 2 is secured to the horizontal shaft 9, the shaft 9 bein mounted somewhat above the horizontal p ane of the axis of the shaft 8. The shafts 8, 9, are positively geared to rotate in the same direction by means of a suitable train of gearing comprising sprockets 10, 11, mounted upon the respective shafts 8, 9, and connected by means of *a chain 12. Driving power may be applied to either one or both any suitable power means, not shown.

5 he rotor 1 comprises essentially a supporting element and a circular series of hammer supports 18 which carry hammers 19, 20, 21, 22. The hammer supports 18 are pivoted at their leading ends to the su porting element by means of pivots 31, and have their trailing ends provided with elongated slots 32 which embrace the pins 30, carried by the supporting element. The rotor 2 comprises a supporting element and a circular series of hammer supports 18 which ;carry hammers 23, 24, 25, 26. The hammer sup orts 18 are pivoted at their leading ends to t e supporting element by means of pivots 31, and have their trailing ends pro vided with elongated slots 32 which embrace the ins 30, carried by the supporting element. he hammers 19, 21, of the rotor 1 are smaller than the hammers 20, 22, the smaller hammers 19, 21, having their extreme outer ends nearer the center of the shaft 8 than are the extreme outer ends of the larger hammers 20, 22. As disclosed, the rotors 1, 2, are so geared that the hammer 22 will always directly approach the hammer 25, While the hammer 25 will always approach the hammer 21, which in turn will always approach the hammer 24. The hammer 24 will always approach the hammer 20, which will approach the hammer 23, which in turn will'approach the hammer 19. The hammer 19 will always approach the hammer 26, while the hammer 26 will always approach the hammer 22. It is not, however, essential to have the driving relation such that these specific hammers approach each other, it being necessary only to have the rotation of the rotors so timed that a hammer of one of the rotors will be passing through the pulverizing zone 27 at all times.

The casing 23 is provided along its upper portions with liners 4, and along its lower )ortions with discharge ggttes 7. The casmg 3 forms annular cham 'rs 29,28, around the rotors 1, 2, respectively. The pulverizing zone or chamber 27. is formed between the rotors 1, 2, and due to the arrangement of the rotors with their axes in dlfierent- The feed plate 15 is reciprocable by means from the pulverizin of a suitable eccentri 16, and is adapted to convey the raw material from the feed hopper 14 to the feed inlet passa 'e 5. A return passage 13 leading tangential y from the annular chamber 28 to an n per ortion of the feed inlet passage 5 is a apte to automatically direct uncrushed material delivereid chamber 27 back into the inlet passage 5. he material discharged through the grates 7 is delivered by gravity from the casing 3 through a suitable di'- charge hopper 6.

During-the normal operation of the d vice, the rotors 1, 2, are rotated in a cloc wise direction as viewed in the figure, an producea continuous current of air in'the annular chambers 28, 29, flowing in the direction indicated by the arrows. The our rent of air flowin in the annular 'chambere 28, 29, causes a slight reduction in pressure\ in the pulverizing chamber 27 between the rotors 1, 2, and maintains'the pulverizing, zone relatively free from air currents. he raw material is fed from the hopper 14 to the feed inlet passage 5 by means of the reciprocating feed plate 15, and is delivered through the passage 5 by gravity. As the raw material drops from the lower extremity of the passage 5 into the ath of the hammers, the large or feeding ammers 20, 22, successively approach and remove the material composlng the projecting portion of the stream of inflowing materlal and hurl the same through the pulverizing chamber 27 As the material thus projected through the pulverizing chamber 27 reaches the lower end of this chamber, the opposed hammer on the rotor 2 advances and strikes the material causing a partial reduction thereof, and returnin the partially reduced material 'upwar ly through the pulverizing chamber 27 The partially reduced material upon reaching the u per extremity of the chamber 27 is struck by the next advancing hammer of the rotor 1 and is further reduced and again returned to the lower end of the pulverizingchamber 27. This course either reduced to a fineness permitting its withdrawal b the air current passing through cham rs 28, 29, or until it is carried beyond the crushing chamber by one of the hammers of the rotor 2. If uncrushed material is carried beyond the )ulverizing chamber 27 by a hammer of t e rotor 2, centrifugal force will immediately act thereon and cause the same to pass upwardly through the passage 13 and back into the inlet passage 5. The fine material withdrawn from the chamber 27 is carried around the chambers 28, 29, and is eventually delivered from these chambers through the grates 7-.

Due to the difference insize of the hamof events continues until the matcrial'is mers 19,21, and the hammers 20, 22, it will be noted that diversionof the stream .of raw material to the pulverizing chamber 27 takes place only when the large hammers 20, 22, reach the stream of inflowing raw material. By making the hammers 19, 21, smaller in size, more raw material is 'rmitted to advance into the path of the ceding hammers 20, 22, and a larger charge is admitted to the pulverizing chamber 27 at each feedin stroke. The smaller hammers 19, 21, are pre erably made of such size, and the s ed of rotation 'of the rotor 1 is preferab y such that these hammers will entirely clear the lower e'xtremit of the inflowin stream of raw material. t will be noted t at with the arrangement disclosed, diverting of. material to the pulverizing chamber 27 takes place twice for each complete revolution of the rotor 1. It should be understood however, that this feature is not essential and the hammers might be pro rly formed to permit feeding of more or ess charges for each revolution of the rotor 1.

If for any reason the normally fixed hase relation of movement of the hammers s ould be destroyed so that the hammers of one rotor due to their overlap with those of the other rotor should strike, or if unbreakable substance should be dropped'into the pulverizer through the inlet passage 5, the hammers upon being obstructed, or upon striking the unbreakable substance, would swin inwardly about their'pivots 31, thus avoi in destruction of the rotary elements. It wi 1 be noted that by causin direct impingementof the material on the moving hammers and avoidin' impact of the material the next advancing hammer or the rotor 2 to carr it into the pulverizin r chamber for furt ier reduction. The location of the rotor 2 at ahigher elevation than the rotor 1, per- 5 mits eilicient feeding of the raw material the direction 0 of entry into the chamber 27. The location of the feed inlet passage 5 as disclosed,

16 causes the feeding hammers to cut the stream of raw material substantially at right angles, and also permits the feeding hammers to properly Inject the raw material into the pulverizing chamber 27.

By employing two oppositely rotating rotors having opposed impact surfaces cooperating for crushing, the speed of rotation of the rotors may be reduced to a,

v ing escaping pieces of uncrushed material "'"ends.

to the feed passage 5, abrasion due to impact of the larger pieces against the casing liners and against the hammer ends, is eliminated. The continuous current of air flowing in the chambers 28, 29, at substantially the velocity of the hammers, and the entrainment by this current of the fine articles of crushed material, also avoids a rasion of this material against the hammer It will thus be noted that all of the elements of the machine cooperate to produce a completed structure in which the elements are subjected to minimum wear.

The material is projected through the pulverizing chamber 27 by the combined ,action of centrifugal force and the impact of the hammers thereagainst. It has been found by actual demonstration that with a may be effected. In

machine of predetermined design, it is necessary to vary the speed when operating upon materials of different characteristics, in order that most efiicient pulverization a properly designed machine the major portion of the disintegration is shown by actual test to take place within the crushin chamber, and but a very small amount of the raw material is reduced by abrasion on the liners 4 and have the material fed into the path of the feeding hammer at its point grates 7. It has also been found that the grates 7 ma be entirely eliminated, but their use wil tend to prevent the discharge of-the few pieces of uncrushed material which may otherwise pass through the machine.

It should be understood that it is not desired to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desiredto secure by Letters Patent, v

1. In combination, a pair of spaced rotors having opposed impact surfaces, means for positively causing predetennined impact surfaces of said rotors to cooperate for crushing, and means for feeding material directly to one only of said rotors and then to the space between cooperating surfaces.

In combination, a pair of spaced rotors having opposed impactsurfaces, means for positively maintaining a fixed phase relation between the impact surfaces of said rotors, and means for feeding material directly to one only of said rotors and then to the space between opposed surfaces of said rotors.

3; In combination, a pair of spaced rotors having opposed impact surfaces, means for rotating said rotors in the same direction and for positively causing predetermined impact surfaces thereof to cooperate for crushing, and means for feeding material to 'one of said rotors above and to one side gfrth'e space between said cooperating surt. In combination, a pair of rotors having overlapping elements provided with opposed impact surfaces and having a crus ing chamber between them, tively rotating said rotors and for causing said overlapping elements to pass through saidchamber at different times, and means for feeding material directly to one of said rotors above and to-one side of said crushing chamber.

means for posi- 5. In combination, a pair of spaced rotors.

having opposed overlapping crushing surfaces movable in the same plane, means for rotating said rotors in the same direction whereby said surfaces'are moved directly toward each other to crush material, and means for feeding material to one of said rotors above and to one side of the space between the approaching surfaces.

6. In combination, a casing, a pair of horizontally spaced rotors within said casing having a crushing chamber directly between-them, the axis of one of said rotors being at a higher elevation than that of the other, means for rotating said rotors in the same direction, and means for feeding material to said crushing chamber.

7. In combination, a pair of co-acting 'ofv sai from the axisof itsrotor than another of rotors *having impact elements rovided with o posed crushing surfaces, at east one element'sf attending farther away said elements, and means for feeding material into the path of said elements. a

8. In combination, a pair of co-actin'- rotors having impact elements, some of sai path ofsaid larger elements. I a pair of co-acting In combmation, rotors having a crushing chamber between them, inlet means communicating with said. chamber, andmeans forming a conduit, ex-

I rotors.

tending tangentially of one of said rotors for returning uncrushed material to said chamber through said inlet means;

10.. In combination, a air of spaced rotors having overlappingimpact elements provided with opposed means for rotating said rotors 1n the same crushing surfaces,

directionabout their axes, said impact elements being movable transverselybf the axes of rotatiomto. permit interfering ele- .ments to clear each other, and means 'for feeding material to the space between said In testim'on whereof, the signature of the inventor is aflixed heret0.

CLIFFORD'J. TOMLINSON. 

